Making Contact

by Sarah Scoles

  “If I had done a brilliant job,” Tarter says, “I could have sat there on my laurels and said I was a good teaching assistant. But I wasn’t such a great teaching assistant. I didn’t prepare enough. So I couldn’t say, ‘Screw you. This is really unfair.’”

  Helping the youth of America with their homework just hadn’t topped her priority list. She was wrapped up in her own academic work, thinking about what her research topic might be. She was now working with astronomer Joe Silk, looking at the ways gas is stripped from spiral galaxies. She thought the research might become her doctoral thesis. But she first had to finish her general courses and take a comprehensive oral test, called a prelim. And then there was also her daughter, Shana. Shana wasn’t even in preschool yet. Every day, Tarter dropped her off at the babysitter and picked her up on the way home. That was anomalous, Bruce notes, at the time: no one sent their kids to daycare.

  When Shana reached elementary school, the bus would drop her off at the Berkeley city library after school. After a few hours of reading and homework she would make her way to Tarter’s UC Berkeley building. If Shana arrived after 5, the door was locked, and she simply waited outside doing cartwheels until her mother realized it was 5:10 and her daughter wasn’t bouncing up and down next to her desk (or until a colleague came by to say, “There’s some little girl doing cartwheels on the stairs”).

  Shana expresses no bad memories of this time period, no sense that her parents weren’t paying attention to her. She does recall, throughout childhood, being surrounded by scientists. “I have memories of falling asleep on scientists’ beds during parties,” she says. “Their dinner-table conversation was rich with the day’s work, the week’s work, and drama. Some of it’s good; some of it, you ignore.”

  When it came time for Tarter to take her prelim exam, the professors grilled her for four hours. But when she passed, she did a cartwheel in the hallway. Trees, it turns out, don’t fall far from apples.

  And also, more conventionally, vice versa. From her earliest years, Shana could often be found lying atop a bear rug at the Danville house, wearing clothes Tarter had made. She stretched her arms along its arms and smiled like her teeth were as big as its teeth. This rug was an heirloom, of sorts. When Tarter was four years old, her father had gone out hunting for a deer and had returned instead with a black bear.

  The family didn’t have a big enough freezer for its body, so Dick prepared it, hung it in the garage, and went out to rent space in someone else’s freezer. Alone with the major ursa, Tarter watched the blood drip from its nose into a pool of plasma on the garage floor.

  She charged her friends a penny to come see it.

  Later, the bear (its meat spoiled) became this rug. When Tarter needed comfort, as a child, she would lie on top of it and wrap its paws around her shoulders, its huge face above hers turning her into a two-headed alien creature.

  Shana, the other bear lover, went on to become the assistant director at the Wilderness Medicine Institute in Lander, Wyoming.

  While Tarter was becoming an engineer, then a mother, and then an astronomer, SETI was busy gaining momentum as a field. The modern SETI movement began with the coincident timing of Frank Drake’s first experiment in Green Bank—pointing radio telescopes at two sun-like stars—and a journal article by astronomers Philip Morrison and Giuseppe Cocconi.

  Morrison had just finished work on the Manhattan Project when he took a professorship at Cornell University. One spring day in 1959, Cocconi came to his office and struck up a conversation about gamma rays and how the universe makes them.

  “We realized we knew how to make them, too,” Morrison said in a 1990 interview for the book SETI Pioneers. “We were making lots of them downstairs at the Cornell synchrotron.” At that particle accelerator, scientists whirred electrons up to high speeds. These negative particles whizzed around a huge circular tube, emitting high-energy radiation—gamma rays. If particle accelerators could make gamma rays, then humans could harness them and beam them out into the universe. Gamma rays, because they have so much energy, travel straight through obstacles in the same way that X-rays go straight through your skin and reveal your bones. Because these rays are basically unstoppable, humans could use them to communicate across interstellar distances. And, perhaps, so could other species on other planets.

  But Morrison thought they should not just accept that gamma rays would make the best missive. They should look at the whole electromagnetic spectrum to find the best wavelength. X-rays, visible light, infrared radiation, radio waves—what about them?

  Gamma rays are great, but making them requires a lot of energy. No one knew how to create ultraviolet radiation. Dust particles in space scatter and absorb visible light—which has a medium-sized wavelength, a middling amount of energy. But long-wavelength, low-energy radio waves: We could make those so easily that we used them to play music in our houses, catch spy planes, and talk to each other. Why not use them to talk to extraterrestrials? And, by extrapolation, why wouldn’t extraterrestrials use them to talk to us? (Looking for radio communications from aliens wasn’t a brand-new idea: in 1924, when Mars slid close past us, radio operators trained their antennas on the Red Planet to see if any Martians were talking.)

  Morrison and Cocconi decided that radio waves represented the best form of interstellar communication. But which radio waves? Radio waves can have wavelengths ranging from 1 millimeter to 100 kilometers.

  Within that wide swath, hydrogen atoms—which make up 74 percent of the universe—emit radio waves that are precisely 21 centimeters long. Cocconi and Morrison thought any astronomically competent society would have discovered hydrogen’s radio waves. And any halfway intelligent species would have built instruments specifically to detect those waves. And they might think that another halfway intelligent species (like humans) would have done so, too. Cosmic communication conceivably might concentrate around this wavelength.

  The two scientists wrote up their ideas in a two-page paper called “Searching for Interstellar Communications,” which appeared in the September 19, 1959, issue of Nature. “The reader may seek to consign these speculations wholly to the domain of science fiction,” they wrote. “We submit, rather, that the forgoing line of argument demonstrates that the presence of interstellar signals is entirely consistent with all we now know, and that if signals are present the means of detecting them is now at hand.”

  And then came this famous line, still a SETI rallying cry: “The probability of success is difficult to estimate, but if we never search, the chance of success is zero.”

  When Morrison and Cocconi’s article came out, the young Frank Drake had already been planning his Green Bank experiment for six months. It even had a name: Project Ozma, after the strange land in L. Frank Baum’s Oz novels. Drake had a longstanding and silent interest in extraterrestrial intelligence, heightened by an experience he’d had in graduate school. Late one night while observing radio waves from the Pleiades, he came across a “narrowband” signal (one that appears at a single frequency, like our radio stations) that looked “intelligent.”

  “What I felt was not a normal emotion,” Drake told William Poundstone, Carl Sagan’s biographer. “It was probably the sensation people have when they see what to them is a miracle: You know that the world is going to be quite a different place—and you are the only one who knows.”

  But when Drake tilted the telescope away from the Pleiades, the signal continued. Because it remained when the star cluster was out of the telescope’s sight, it couldn’t be coming from the cluster: It had to come from Earth. Still, the possibility of that miracle’s reality stayed with him. After that, whenever he thought about using a particular telescope he would ask himself, “Could this be used to search for intelligent life?”

  “The answer was always, ‘No,’” he said in the book SETI Pioneers, “until we came to modern radio telescopes.”

  Drake went to work with these modern radio telescopes, at the National Radio Astronomy Observato
ry in Green Bank, West Virginia. Fifty miles from a grocery store, the Green Bank observatory is a scientific oasis in the middle of the Monongahela National Forest. It was a brand-new facility when Drake was contemplating his first experiment, cobbled together from bought-up farmland. Engineers and technicians grew radio telescopes from the ground up. They lived in pop-up construction-worker shacks and the eminent domain of farmhouses. According to Drake’s calculations, the first telescope they finished at the site—the 85-foot-wide Tatel Telescope—could detect broadcasts as strong as the ones humans then made, if those broadcasts came from star systems up to 10 light-years away.

  A few times a week, a group of Green Bank scientists would have lunch at a diner (which we might as well call “the diner,” as it was the only one, but which they jokingly called Pierre’s). And one afternoon, as snow fell on the only highway in or out of town, Drake told them about his conclusion: they could do a search for extraterrestrial intelligence right then and there. Lloyd Berkner, then director of the observatory, stuck a fry in his mouth and took a sip of soda.

  “I like it,” he said.

  The Green Bank crew was isolated not just from fresh produce but also from outside ideas about SETI. But really, no one talked about it, anyway. “The subject was not discussed,” Drake continued in the interview. “There was no way to know who was interested, just no way to make contact or to learn of other people’s interests.”

  So the Green Bank scientists set about silently making their equipment and planning their experiment, keeping it quiet so neither their colleagues nor the press would descend. And then they saw the Cocconi and Morrison paper, laying out how and why to do a search exactly like the one they were planning. By then, astronomer Otto Struve had become the observatory’s director, and he wanted his institution to receive credit for its alien ideas. He went public with the project at a lecture he gave at MIT a month later.

  Drake quietly continued his work. Each morning of the experiment, he had to climb up to the garbage-can-sized instrument—an amplifier, which turns up the volume on signals from space—hanging above the telescope’s dish. It required adjustment every morning.

  “When I think of Project Ozma,” he said in SETI Pioneers, “I recall how cold it is at Green Bank at four in the morning.”

  Drake’s project showed up in the pages of Time, where Hewlett-Packard executive Bernard Oliver saw it. He became a little obsessed. The next time Oliver visited Washington, DC, just a few hours from Green Bank, he called Drake at the observatory, an event Drake related in SETI Pioneers.

  “Would it be possible to visit you and see what the apparatus is you’re using in Ozma?” he asked.

  “I’d be very happy to have you,” Drake responded, “but you can’t get from where you are and back in a day.”

  “Don’t underestimate me,” Oliver said.

  The next morning, he flew in on a small plane and landed on the tiny airstrip next to the big telescope. Oliver’s chutzpah, his electronics wizardry, and his fixation on alien intelligence netted him an invitation to the SETI meeting of the century, one called by J. Peter Pearman of the National Academy of Sciences.

  Now that the idea of ET was out in the world, Pearman wanted to build federal support for it. The best way to do that, he decided, was to convene a scientific conference on the topic, held where the whole thing started—Green Bank, conveniently a town where no one would notice a bunch of eggheads talking about aliens. He presented the meeting idea to Drake, and together they drafted a list of invitees.

  Now, and to some extent then, it reads like a who’s who of the scientific frontier: Carl Sagan, just 26 and almost an interloper; Melvin Calvin, who won a Nobel Prize in Chemistry during the meeting; John Lilly, a researcher who wanted to communicate with dolphins; Morrison; Oliver; and a few others. The meeting took place in the dormitory lounge at the Green Bank observatory.

  To begin, Drake stepped up to the chalkboard and scrawled an equation. He didn’t call it the Drake equation, but that’s what scientists have called it ever since. It listed the seven factors that lead to the development (or not) of communicative, intelligent life. If they could figure out these factors, Drake said, and multiply them together, they would know how many civilizations populated the galaxy.

  • How often do life-friendly stars form?

  • What fraction of those stars host planets?

  • On how many of each star’s planets could life live?

  • What fraction of those planets actually develop life?

  • What fraction of that life evolves the kind of intelligence we would call intelligence?

  • What fraction of that intelligent life communicates across the cosmos?

  • And how long do those communicative civilizations last?

  Drake turned around to face his distinguished audience. So?

  They discussed the numbers for three days, coming up with a final estimate of “between 1,000 and 100,000,000” communicative civilizations in the galaxy. Because their talk occasionally diverted into dolphin territory—discussions of whether dolphins counted as intelligent (meaning intelligence arose at least twice on Earth—three times if we count what we now know about the consciousness of octopi!) and, more importantly, whether dolphins could get erections on command—the group was dubbed, after the fact, the Order of the Dolphin.

  In October 2010, the Green Bank observatory had a conference—Ozma@50—to commemorate the 50th anniversary of Drake’s earliest SETI work and that first conference. The observatory looked much as it did in Drake’s day, with the notable addition of the white-paneled Green Bank Telescope, taller than the Statue of Liberty and wide enough to cradle 2.5 football fields. But the town hasn’t grown. Its population sign reads 143. Even elementary schoolchildren get the first few days of hunting season off from school. Tourists—often in caravans of motorcycles—driving along the one-way-in-one-way-out US 250 get bucolic views: barns, mountain ridges, analog gas pumps. Then, when they maneuver through a bend in the road, they find hulking technological structures plopped in this middle of nowhere. Next to these high-tech telescopes stand the buildings from the 1950s and 60s, which have been kept in a historical icebox.

  Drake returned to town for the Ozma@50 conference, as did 48 others, including Tarter’s husband, Jack Welch, a radio engineer. For the opening reception, guests gathered in the same low-ceilinged room where Drake wrote the Drake equation before it became the Drake equation. Now, a plaque with this formula hangs humbly over the fireplace. Aside from that, the space is the same. The same cheesy chandelier, reminiscent of a lava lamp, still hangs over the table. Orange vinyl couches and flat turquoise carpet still vie for your eyes’ attention. A hinged chalkboard might actually be the same one Drake wrote on. In SETI, it seems, not much has changed.

  Barney Oliver, of the rogue plane flight into Green Bank, became a SETI advocate, speaking publicly whenever he got—or gave himself—the chance. NASA decided to put his general’s voice to use: they asked him to chair a committee commissioned to think about “what would be required in hardware, manpower, time, and funding to mount a realistic effort, using present (or near-term future) state-of-the-art techniques, aimed at detecting the existence of extraterrestrial (extrasolar system) intelligent life.” The committee met over the course of 10 weeks, dreaming up the specifics of a SETI scientist’s dream telescope. What technological beast could best see—or hear—fantastical beasts on other planets?

  The document to emerge from the committee, called the Cyclops Report, presents a 250-page elaboration on its own introductory statement: “We now have the technological capability of mounting a search for extraterrestrial intelligent life.” It describes potential signs of such civilizations and a potential detection system—called the Cyclops, specced down to a capacitor—that could pick up a message. The scientists suggested the Cyclops, a telescope composed of many smaller antennas that would together have an area of 100 square kilometers, be built in a modular fashion. They could erect a
few antennas and see whether any extraterrestrial broadcasts came through. If not, they would build more antennas, making the telescope bigger and more sensitive to fainter broadcasts. If they still found nothing, they would expand the array out even more. But when the federal government saw the total price tag ($6–10 billion), they put their hands on their pocketbooks and ran away. Although NASA intended the Cyclops Report to make SETI seem doable, the team actually accomplished the opposite.

  Nevertheless, they had produced a thorough and (strange as it sounds) compelling-to-read document that remains relevant 44 years later, when the computers that ring in our pockets are much more powerful than the PDP 8/S. Some call the report SETI’s bible. Tarter still gives it to graduate students to teach them to sift radio signals from outer space static. She’s like a zealous convert, passing along the scripture that first inspired her.

  Bowyer, the professor Tarter surfed with when she crashed into the coral reef and whose class she’d TAed poorly, had read the Cyclops Report. Although that particular big telescope would never be built, he had a smaller-scale (and more cost-effective) idea: a SETI instrument he could stick on the back of any existing radio telescope. That telescope could do its regular work, and this instrument would make a copy of the incoming radio signal—a copy that scientists could use for SETI work, leaving the original copy intact for regular science. Without losing any information, Bowyer could do SETI at the same time that another astronomer did his or her own research. Not exactly symbiotic, and not exactly parasitic. Commensal.

  “Piggybacking,” he called it. Bowyer began shopping this idea around. Jack Welch soon said he had a telescope Bowyer could try as a test. It was at the Hat Creek Radio Observatory, in far northern California, off a rural logging route so dangerous that Welch had learned to fly a plane just to avoid driving there.